8-4-1 Headers (Video)

[JTM88]

I had a similar sound after installing long-tube headers, although the circumstances were a little different. Whenever I made a left turn at speed through an intersection, the engine would tilt just enough for the passenger-side header to contact the A/C line.

Since yours happens on right turns, it makes me wonder if the header is contacting the steering shaft instead.

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[WItoTX]

OP, how do your motor mounts look? Might be a good time to replace those as well if the motor is moving and the headers are out.

 

[TreeFiddyAre]

Will be interesting what they find wrong.
My fake money bet is on the steering shaft to header tube interference especially knowing the steering shaft has to be disconnected for header install.

She is going to the shop in the am...I might just be that but what is odd is how intermittent has become but it is always in the same spot and the faster I go the faster the vibration is...I hope its just interference and not an electrical component

 

[GregO]

the faster I go the faster the vibration is...

As speed increases so does engine RPM’s and with that comes higher vibration frequencies.

I’ll raise my fake money bet double or nothing it’s steering shaft to header clearance and possibly a slight motor shift to one side for added clearance. 304 SS grows a lot when hot.

 

[TreeFiddyAre]

As speed increases so does engine RPM’s and with that comes higher vibration frequencies.

I’ll raise my fake money bet double or nothing it’s steering shaft to header clearance and possibly a slight motor shift to one side for added clearance. 304 SS grows a lot when hot.

The more I drive it, the more I'm convinced this has something to do with the EPAS.

Here's where it gets interesting...

If I set the steering to Comfort, the vibration/buzz is much slower and less aggressive. Switch it over to Sport, and the frequency increases noticeably. It also scales with vehicle speed. If I quickly turn the wheel at 10 mph, the vibration is there, but at 30 mph it's much more aggressive. The fault only exists within a tiny window of steering wheel rotation (about the 2:45–3:00 position), and once you rotate past that point it disappears immediately. The other direction is very intermittent and when it goes off its right off 12 o'clock .

The best way I can describe it is that it feels like the steering rack or EPAS motor is having an identity crisis trying to figure out how much "fake weight" it wants to add to the steering. It's almost like the assist motor starts oscillating because it's confused about what it should be doing in that exact steering position.

So, long story short:

- Headers aren't touching anything.
-Plenty of clearance to the steering shaft.
-No witness marks anywhere.
-The issue is both speed-dependent and drive-mode dependent, which makes me think it's electronic rather than mechanical. It sounds and feels far tooo much like an electrical motor trying to create a sensation at the wrong time

She heads to the stealership Tuesday at 10:00 AM.

Let's see if my extended warranty and the service advisor can peacefully coexist with a set of long tubes... Wish me luck

 

[GregO]

She heads to the stealership Tuesday at 10:00 AM.

Let's see if my extended warranty and the service advisor can peacefully coexist with a set of long tubes... Wish me luck

What was the dealer diagnosis and corrective action ?

 

[TreeFiddyAre]

Sooo...

The dealer called after I dropped it off and said it was a clearance issue. My immediate response was, "No fuggin' way..." I asked, "Is the car still on the lift? Mind if I come see?"

Drove over, crawled underneath, and sure enough... they were right. From the top it looked like there was plenty of daylight, but from underneath it was a whole different story. The header was making Tiny contact, which explains the feedback I was getting through the steering wheel. It's funny how a couple of micrometers can turn into an entire diagnostic adventure.

She's all sorted now. Crisis averted. My steering wheel is no longer trying to communicate with me in Morse code.

Next up... the ESS supercharger is officially on order. Now I just need injectors, a voltage booster, and then begins what I'm sure will be the completely stress-free, never-frustrating tuning saga.

Question for the boosted crowd...

Ideally I'd like to have multiple tunes available depending on what fuel I'm running. Here's what I'm thinking:

93 octane "Dad Mode" – Rev limiter around 6,000 rpm (or even a little less). Basically a safe, conservative tune for those times I'm nowhere near E85 and just need to get from Point A to Point B without doing anything stupid.
93 + Boostane Premium – Roughly 100–102 octane (32 oz to 8 gallons of 93). I already run 4 oz of Boostane in every tank of 93 now just for a little extra knock resistance.
Pump E85 – Around me it's consistently been E75 to E83, so I'd definitely want a tune for that.
VP C85 + Ghost Cam (flame suit already on...) My old car absolutely loved C85 compared to pump E, and one of my bikes did too. That fuel is magic. Expensive magic... but still magic.

So... what are you guys using these days for handhelds?

Originally I wanted to go with an nGauge, but those have pretty much disappeared. Is there anything out there now that can comfortably store 4 tunes? Also still on the fence about who I'm going to use for tuning, so I'd love to hear some recommendations.

And if anyone has a line on a clean set of used ID1050X/XDS injectors (or larger), let a brother know. I'll send them out to be cleaned and flow-tested before they ever go in the car.

Appreciate any advice. Parts are finally starting to roll in, and this thing is getting dangerously close to becoming expensive.
Oh I really like the QA-1 Carbon DS

 

[galaxy]

Slightly on topic - look at Sunoco E85R. I get that. It’s a slight chunk cheaper than the VP and IMO, just as good. Consistently tests out of the barrel at 90-92. Like you, my car absolutely loves it.

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